Hi,
I have a 2006 3.0si and have recently used Renovo's Soft Top Reviver with great results. Very easy to apply, and any worries I had about doing it prior were for no reason.
I only gave it one coat, and used less than half of the bottle. I had previously used BMW roof cleaner and impregnating agent which always made the soft top look good, but after the Reviver it now looks nice and dark again. Couldn't be happier with the result.
I masked off the rear window as well as the windscreen with masking tape and newspaper and used a 2" brush to apply the solution. I did have a few drips fall on the side windows and a couple on the body, but they wiped off very easily with a damp cloth. A few spots on the glass that even dried came off with my normal glass cleaner.
It really was an easy process, and the results are well worth it. After it had dried I used a soft brush to "soften" the roof fibbers again - hard to explain what I mean here, but it'll make sense when you do it!!
Cheers,
Nelson.